package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.SimpleRedisLock;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.time.LocalDateTime;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.UUID;
import java.util.concurrent.*;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
@Slf4j
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {


    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    RedissonClient redissonClient;
    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;

    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }

    //线程池
    private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();

    //在当前类初始话完毕以后执行
    @PostConstruct
    private void init() {
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }
    /*    //阻塞队列
        private BlockingQueue<VoucherOrder> ordersTasks = new ArrayBlockingQueue<>(1024 * 1024);
        //在当前类初始话完毕以后执行
        @PostConstruct
        private void init() {
            SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
        }

        private class VoucherOrderHandler implements Runnable {

            @Override
            public void run() {
                while (true) {
                    try {
                        VoucherOrder take = ordersTasks.take();
                        handleVoucherOrder(take);
                    } catch (Exception e) {
                        log.error("");
                    }
                }
            }
        }*/

    private class VoucherOrderHandler implements Runnable {
        String queueName = "stream.orders";

        @Override
        public void run() {
            while (true) {
                try {
                    //获取消息队列中的订单信息
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed())
                    );
                    if (list == null || list.isEmpty()) {
                        continue;
                    }
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    //将消息从<key，value>,<key，value>,<key，value>,转化为对象
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    //存储消息到mysql
                    handleVoucherOrder(voucherOrder);
                    //使用ack把消息从pendinglist中去除
                    stringRedisTemplate.opsForStream().acknowledge(queueName, "g1", record.getId());
                } catch (Exception e) {
                    log.error("处理订单异常", e);
                    handlePendingList();
                }
            }
        }

        private void handlePendingList() {
            while (true) {
                try {
                    //获取pending-list中的订单信息
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1),
                            StreamOffset.create(queueName, ReadOffset.from("0"))
                    );
                    if (list == null || list.isEmpty()) {
                        break;
                    }
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    //将消息从<key，value>,<key，value>,<key，value>,转化为对象
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    //存储消息
                    handleVoucherOrder(voucherOrder);
                    //使用ack把消息从pendinglist中去除
                    stringRedisTemplate.opsForStream().acknowledge(queueName, "g1", record.getId());
                } catch (Exception e) {
                    log.error("处理pending-list订单异常", e);
                    try {
                        Thread.sleep(20);
                    } catch (InterruptedException ex) {
                        throw new RuntimeException(ex);
                    }
                }
            }
        }
    }

    //处理线程里的订单
    private void handleVoucherOrder(VoucherOrder voucherOrder) throws InterruptedException {
        Long id = voucherOrder.getId();
        RLock lock = redissonClient.getLock("lock:order" + id);
        boolean isLock = lock.tryLock(1, TimeUnit.SECONDS);
        if (!isLock) {
            log.error("不允许重复下单");
            return;
        }
        try {
            proxy.creatVoucherOrder(voucherOrder);
        } finally {
            lock.unlock();
        }
    }


    private IVoucherOrderService proxy;

    //主线程
    public Result seckillVoucher(Long voucherId) throws InterruptedException {
        Long userId = UserHolder.getUser().getId();
        proxy = (IVoucherOrderService) AopContext.currentProxy();
        //获取订单id
        long orderId = redisIdWorker.nextId("order");
        Long result = stringRedisTemplate.execute(SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(),
                userId.toString(),
                String.valueOf(orderId)
        );
        int r = result.intValue();
        if (r != 0) {
            return Result.fail(r == 1 ? "库存不足_lua" : "不能重复下单_lua");
        }
        //TODO 保存阻塞队列
//
//        //4.创建订单，返回订单id
//        VoucherOrder voucherOrder = new VoucherOrder();
//        voucherOrder.setId(orderId);
//        voucherOrder.setUserId(userId);
//        voucherOrder.setVoucherId(voucherId);//代金券id
//
//        //往阻塞队列里添加订单
//        ordersTasks.add(voucherOrder);

        //在主线程获取代理对象

        return Result.ok(orderId);
    }
/*    //主线程
    public Result seckillVoucher(Long voucherId) throws InterruptedException {
        Long userId = UserHolder.getUser().getId();
        Long result = stringRedisTemplate.execute(SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(),
                userId.toString()
        );
        int r = result.intValue();
        if (r != 0) {
            return Result.fail(r == 1 ? "库存不足_lua" : "不能重复下单_lua");
        }
        //TODO 保存阻塞队列
        long orderId = redisIdWorker.nextId("order");
        //4.创建订单，返回订单id
        VoucherOrder voucherOrder = new VoucherOrder();
        voucherOrder.setId(orderId);
        voucherOrder.setUserId(userId);
        voucherOrder.setVoucherId(voucherId);//代金券id

        //往阻塞队列里添加订单
        ordersTasks.add(voucherOrder);

        //在主线程获取代理对象
        proxy = (IVoucherOrderService) AopContext.currentProxy();
        return Result.ok(orderId);
    }*/

    @Transactional(rollbackFor = Exception.class)
    public void creatVoucherOrder(VoucherOrder voucherOrder) {
        //一人一单
        int count = query().eq("user_id", voucherOrder.getUserId()).eq("voucher_id", voucherOrder.getVoucherId()).count();
        //
        if (count > 0) {
            log.error("用户已经购买一次");
            return;
        }
        //3.2库存充足扣减库存
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock-1")
                .eq("voucher_id", voucherOrder.getVoucherId()).gt("stock", 0)
                .update();
        if (!success) {
            return;
        }
        save(voucherOrder);
    }
}
